Shape-cutting machine



April 14, 1942. s. R. OLDHAM 2,279,338

7 SHAPE cu'rnue momma Filed- Aug. 26, 1937 6 Sheets-Sheet 1 lNVEN'i'OR R.OLDHAM ATTORNEY April 14, .1942. s. R. OLDHAM 2,279,338-

SHAPE CUTTING MACHINE Filed Aug. '26, 1937 6 Sheets-Sheet 2 v lllllllllllllllllllllill llllllll v INVENTOR SAMUEL R.OLDHAM ATTORNEY April 14, 1942. s, R, QLDHAM 2,279,338.

- SHAPE CUTTING MACHINE I Filed Aug. 26, 1937 l s Sheets-Sheet s INVENTOR SAMUEL R.OLDHAM ATTORNEY pril 14, 1942. s. R. OLDHAM SHAPE CUTTINQ MACHINE Filed Au 26, 19s? 6 Sheets-Sheet 4 SAMUEITEEPSHAM- ATTORNEY April 14, 1942. s. R. oLDHAM 2,279,338

- SHAPE cuwcrme momma Filed Aug. 26, 1937 s Sheets-Sheet 5 \NVENTOR I SAMUEL R. OLDHAMv ATTORNEY SHAPE CUTTING MACH'INE INVENTOIR SAMUEL ROLDHAM ATTORNEY Patented Apr. 14, 1942 Oxweld Acetylene Company, a corporation of West Virginia.

Application August 26, 1937, Serial No. 161,085

25 Claims.

This invention relates to the art of thermal metal-working by oxy-acetylene torches and particularly to an improved 'thermalmetalworking machine of the type capable of universally moving one or more oxy-acetylene torches in a plane over work to be treated. Although the principles of the invention may be employed with any type of machine, the movement of which is controlled by a pattern, it will be described in connection with oxy-acety-lene shape-cutting machines.

Shape-cutting machines in this general class have been provided with various types of pro- -pe1ling means including differentially actuated rollers adapted to frictionally engage and follow a raised templet. Others have been provided with interchangeable hand-guided tracer devices adapted to follow a pattern within the plane of a table.

Difiiculties have been experienced with the use of these prior-known shape-cutting machines because their construction is such that excessive inertia forces are setup when the propelling means changes itsdirection of movement, i. e., when the tracer follows a-curved path or turns a sharp corner. The absorption of these forces by the apparatus impairs the accuracy with which cuts can be produced.

The pattern tables used in' conjunction with prior-known devices of this type do not afford means to satisfactorily support the templets and still maintain an uninterrupted plane surface I upon which patterns may be sketched or prints fastened, and upon which a hand-guided tracer unit may operate.

Flexible tubing in the form of rubber hose, is usually employed for conveying the oxygen and acetylene or other fuel gas to the cutting torches. Prior known machines of the type referred to usually supported these gas conveying tubes at a point substantially above the universally-movable mechanism; thus, the vibrations incident to their movement with said mechanism are amplified and transmitted directly to the blowpipe support, consequently affecting the accuracy of the cut.

An object of this invention is to provide a shape-cutting machine of the' character de scribed that will be easy to operate, accurately reproduce any type of complicated pattern, and overcome the difiiculties encountered in using known devices of this character. -Other objects include: the provision of a propelling unit that will drive a pair of oppositely-rotatable traction elements, or an interchangeable hand guided tracing device and yet require a minimum of inertia to be overcome in following complicated outlines; the provision of interchangeable, automatically-guided and hand-guided propelling devices so located that either is readily accessible to the operator; the provision ofa pattern table adapted to adequately supporta raised pattern templet and still maintain a plane surface upon which patterns may be drawn, or prints fastened.

and upon which a hand-guided propellinglmechanism may accurately travel; and the provision of an oxy-acetylene shape-cutting machine capable of supporting oxygen, acetylene, and electrical conduits in such position that their move-' ment. will not detrimentally afiect the cut produced by the cutting torch.

Other and more specific objects of this invention includez the provision of means for limiting the universally-movable mechanism to straight line motion; the-provision of a combined unitary assembly including a variable speed transmission and a difierential unit capableof universally moving the cutting'torch in a plane over work to be shaped; the provision of means adapted to compensate for the width of the kerf' produced incident to cutting, thus enabling oversize as well as undersize cutting; and the provision of a bevel cutting attachment adapted to produce accurate bevels when the propelling means travels in a curved path.

The above and other objects and the novel features of this invention will become apparent from the following description taken with the accompanying drawings, in which: v

Fig. 1 is a perspective view of a shape-cutting machine embodying the principles of this invention;

Fig. 2 is a side elevational view of a portion of the machine disclosed in Fig. 1, broken away in part to show the brake construction of -one of the carriage wheels;

Fig. 3 is an end elevational'view of the mechanism of Fig. 2, disclosing the under-slung wheel construction of the upper carriage;

Fig. 4 is an elevational view, partly in section, showing a portion of the traction-propelling apparatus, including the steering mechanism, of Fig. 2, but rotated through I Fig. 5 is a vertical sectional view taken substantially along line 55 of Fig.4;

Fig. 6 is a top plan view of the driving mechanism shown in Fig. 4, with the top cover removed; s

Fig. '7 is a vertical sectional view of an interchangeable traction-propelling device capable of being Substituted for the unit supporting the pair of traction elements of Fig.

Fig. 8 is an elevational view, partly in section,

of a bevel cutting attachment for the machine shown'in Fig. 1; and

Fig. 9 a vertical sectional view taken substantially along line 8-9 of Fig. 1, showing the arrangement of parts for adjusting the torch independently of the tracing unit.

Referring to Fig. 1 of the drawings, the invention is disclosed as applied to a shape-cutting machine, including a universally-movable can iage mechanism C provided with one or more thermal implements such as blowpipes or cutting torches T at one end thereof, adapted to be universally moved in a plane over work W to be cut on the pattern table T, or the plane surface provided by said table. 4

A work-supporting table Ill and an apparatussupporting table II made up of a number of cast iron sections rigidly bolted together, are arranged in parallel relation. A pair of rails l2 and I3 fastened to the sides of the table fl, and provided with buifers ll at each end thereof (only one of which is shown) are adapted to support a lower-carriage I5 for limited movement longitudinal of the supporting table II. The absolute straightness of these rails is an important factor in assuring accurate results, and they are therefore built to withstand the heat incident to cutting heavy members by oxy-acetylene cutting torches. preferably made of semi-steel, heat-treated to relieve all thereby assuring perfect alignment under the most severe conditions.

The lower carriage l5 comprises frames It at the front and rear of the carriage C adapted to ride along the rails l2 and I3. The foremost rail 12 is constructed to accommodate peripherally-grooved wheels (not shown) located at the torch-end of the lower carriage I5; and enclosed guards I6; and the rail [3 is provided with a groove adapted to accommodate tongued-wheels (not shown) at the rear of said caniageand likewise enclosed in similar guards 16. A pair of transverse rails l1 and I8 adapted to support an upper carriage H, are rigidly fastened to'the supporting frames l6 between the wheel guards l6 and I6". These rails are likewise provided with bufiers similar to those on rails 12 and [3. The supporting frames l6 are preferably constructed of cast iron and in such fashion that the bottom' of the upper rails l1 and 18 which rest on them are below the center of the wheels of the lower carriage l5, thus lowering the center of gravity of the entire carriage structure. The front and rear wheels of the lower carriage IS on the far side of the machine as it is represented in Fig. 1, are preferably connected by an enclosed shaft (not shown) so that wheel action at both ends of the lower carriage will be identical.

All four wheels of the lower carriage l5 are The rails 12 and I3 are 4 of castiron, and are provided with anti-friction bearings completely enclwed, and lubricated for the life of the machine. The front wheels are protected by aluminum guards I6, and heavier cast iron guards l6" protect the rear wheels and assist in counterbalancing the weight of the overhanging parts at the torch or front end of the'machine. Rail wipers 2. are provided at both sides of each whe'elpand those on the near side of the carriage l5, both front and rear, are constructed of wire brake lining to provide a brake which can be regulated by an adjusting screw 2|. The other two rail wipers are of a high grade felt, and are held against the rails by small springs.

The upper carriage rails I1 and ll are firmly secured to the front and rear frames It of the lower carriage l5, and are constructed of a highstrength extruded aluminum alloy. Exact. alignment of the rails I1 and I8 is accomplished by a series of tie rods at regular intervals throughout the length of these rails.

The upper carriage I9 is constructed and arranged to support substantially all of the operating controls, most of which are in duplicate so as to be accessible from both the cutting and tracing postions of the shape-cutting machine. The forward end of the carriage I9 is adapted to support the cutting torch T, and therefore difficulties have been overcome by constructing the upper carriage ll of a special hollow casting made of high-strength aluminum alloy. iving an efficient strength-weight ratio. In order to permit an even distribution of the heat absorbed by the forward portion of the carriage ll, this casting has beenprovided with a series of apertures 22 which serve a dual fimction, name- 1y. to lighten the upper carriage I, and to permit circulation of air therethrough so that the heat of cutting may be distributed, and equal expansion thus secured throughout the length of the casting.

Referring to Fig. 3, the upper carriage I! travels on the upper carriage rails l1 and II by means of eight wheels, four of which ride on the under lips 23, while the remaining four ride on the upper, lips 2| of these rails.

One pair 25 of these wheels is adapted to engage the under lip 23 of the rails l1 and II at the rear of the upper carriage I! for the purpose of carrying the loadimposed by the over-hung weight of said carriage. The wheels or rollers 25 are supported by a bearing sleeve 26 pivotally mounted on the rear of the carriage I! by a pivot bolt 21, as shown in Fig. 3, allowing the overhanging carriage l9 to press the wheels 2' firmly against the underlip 23 of rails I I thereby compensating for any structural irregularities in the rails which would affect the motion of the carriage l9 during its travel. One of the wheels 25 is fixed to a rotatably-mounted shaft 28, while the other wheel is journalled on the rotatablymounted shaft. An upper pair of wheels 3| provided at the rear of the carriage I! ride on the upper lips 24 of the rails l1 and I8 and aid in preventing tilting of the carriage [9.

As shown in Fig. 2, two pairs of wheels are located somewhat further forward on the carriage l9, one pair 3| riding on the under lip 23 of the rails, and" the other pair 32 on the top of the fad-vases 'railsll and II. Thesewheelsflassistthewheeis 25 in carrying the over-hung blowpipe load.

while the under pair ti cooperates with wheels 30 to prevent tipping of the carriage ll.

The eight upper carriage wheels are grooved to fit corresponding tongues formed by the upper and under lips 24 and II of the rails II and II, and all of these wheels are provided with the provided for the lower carriage wheels. Guards 38 and "are mounted on the upperacarriage ll riage it supports a plurality o'f threaded comwfl .nectors in position to be securely attached to the attached to the rear upper surface oi the car-1 individual brass pipes passing within andlongitudinally oi the carriage is. This. connector assembly accommodates an oxygen supply a preheat oxygen'supply 41, .an acetylene supply- '40, and inlet' and outlet waterconnectiofis ll.

same double felt-seal ball bearings 'as those The forward portion of, the carriage I0 is provided with plates ii and I6 adapted to support a like number of connectors associated with the in position to cover and protect the upper wheels 7 30 and ",and spring-held felt wipers II are provided. at the trout and rear of of these wheels for maintaining the upper rails II and is clean. It willlbe apparent that the arrangement of blowpipe torch T in a plane over work to be shaped lt is often desirable to limit the movement of the-torch T to a straight line, either longitudinally of theirails l2 and it, or transversely thereof. This may be accomplished by limiting the-carriage mechanism C to movement along only one of its paths. In the present instance a brake mechanism-B is associated with one of the wheels 32 of the upper carriage it, and a like the several wheels of the upper carriage it affords great stability combined with complete forward ends of the brass pipes, which connectors accommodate an oxygen delivery tube II, a preheat oxygen delivery tube 63, and an acetylene delivery tube It and cooling water connections. The plate 55 also supports a housing It within which islocate'd a preheat gas operating valve which may be actuated by an operating lever 51. The short-lengths of the flexible tubing provided for joining the various connectors to the cutting torch T limit the unsupported length of gas passages to a minimum, and thereby eliminate any vibrations incident to swaying of the conduits during operation of the machine. Flow of the cutting oxygen to the torch T is controlled I by the operation of a valve located in thegasconveying brass pipe within the carriage l9". A

' valve-operating lever 58 is located midway of the mechanism is associated with one of the wheels of the lower-carriage ll. Because the mechanism for limiting the carriage to movement along either of its paths is identical, the same will be described only in connection with the wheel 32 of the upper carriage it. As shown in Fig. 2, this limiting mechanism comprises a pair of brake shoes Iii associated with the periphery of the wheel 32, each of which is mounted onone of a pair of supports 4| depending from the interior of the guard 33. Springs 42 are connected to the guard 33 and to the respective brake shoes so asv to urge the same into frictional engagement with the outer periphery or rolling surface of the wheel 32. A toggle joint 43 is mounted on the wheel guard 33 and is adapted upon movement between two positions to release the brake shoes, and to permit springs 42 to eflect frictional engagement between said shoes and the wheel 32. A crank arm 44 (see Fig. 1) is connected to a link of the toggle joint 43 and extends outside of the guard. When the crank 44 is turned, the wheel with which the limiting mechanism is associated is either released or held length of the carriage i9, and is interconnected with a lever 58 located at the. front of the carriage. Since the levers 58 and is are interconnected, the cutting oxygen supply may be turned off or on by either, without the necessity of manipulating the cutting oxygen valve ,on the torch T. 1,

The torch T may be adjusted over the work W independently of thecarriage C. Referring to,

Figs. 1 and 9, the torch T is attached to'a clevis support 80 within which is located a guide member Ill. The support 60 is adapted to telescope with a support 6i fixed to the front of carriage IS. The guide 60' extends beyond the support 60 and is provided with a rack 6| in mesh with a pinion 82. The pinion 62 is mounted within the support if, and is rotated by a handle 63. Thus it is seen that relative movement between the torch T' and carriage C may be effectively accomplished, and any adjustment may be maintained .by locking means 84.

Angular adjustment of the torch T is also providedby' two inter-pivoted aluminum brackets 65 and 88. The bracket 85 comprises a ground stainless steel tube 81 within a tubular rnember stationary. The use of spring-controlled brakes R i l-5. 52- 3 81- .i t. thc rear and front respective- Fig. 5).

68 held between the ends of a clevis O9. Tube 51 is securely held in position byv means of a draw bolt 1.0, and the bracket 88 is held to the tube 81 .by another draw bolt H. A third draw bolt 1! permits adjustment of the torch T relative to the bracket 86. Vertical adjustment of the torch T is effected by rotating a handwheel 50 fixed to a pinion supported on the bracket It and meshing with a rack integral with said torch. From the foregoing description it is apparent that the torch T can be inclined at different angles in two planes, or at compound angles, and for accurately inclining the same, the brackets 85 and 6B are provided with adjustable micrometric positioning scales.

The traction-propelling device P comprises a motor M, rigidly mounted on the upper carriage I! in operative association with a combined variable-speed transmission and differential unit V- which drives a pair of spaced shafts 15,16 (see These shafts are adapted to be connected to a pair of oppositely-rotatable, tractionpropelling elements ll, 18 arranged to engage a raised templet or pattern I8 on table T. Shafts 18. 16 are further adapted to interchangeably accommodate a hand-guided traction-propelling unit H; (see Fig. 7), adapted to follow a predetermined pattern substantially within the. plane of the top surface of pattern table T'.

Referring to Fi of the drawings, one form n of a combined variable-speed transmission and differential unit for the traction-propellingqdevice P comprises a worm 88 fixed to the extended shaft of the motor M, and indriving engage ment with a worm gear 8| Journalled on an extended power shaft 82' which is supported by bearings 88 and 88. The worm gear II is provided with a pinioned hub 85 adapted to mesh with a pair of spur gears 88 and 81 journalled on diametrically spaced pins 88 and 88 on a hubbed flange plate 80. A second hubbed flange plate 8| is journalled on the hub plate 88 and is adaptasvasas Y i pelling device H.v Inthe presentembodiment of the invention. this has been accomplished by providing a pair of independently-rotatable mutually telescoping shafts I88 and Ill, adapted to support a pairof oppositely-disposed bevel gears I88 and I88, respectively. The bevel gear I88 is fixed to the'tubular shaft I88 by -a set screw. while the bevel gear I88 is fixed to the internal shaft I84 by a pin II". A bevel gear III is fixed to the shaft 82 in position to mesh with the bevel gears I88 and I88; thus rotation of 'shaft 82 will ,cause the axially aligned driving shafts I88 and I to be rotated in opposite directions and at the same speed. The shafts I88 and I are further provided with extended gearportions I88 and II. at their lower ends fora purpose to be described later.

ed to support an internal ring gear 82 near its periphery. The ring gear 82' is adapted to mesh with the pair of pinions 88 and 81 thus forming a I planetary arrangement therewith. The outer periphery of the flange plate 8| is provided with a locking means in theform of gear teeth 88 adapted tobe engaged'by an inter-meshing bellcrankLbrake-device 88 pivotally mounted within the transmission housing .by a pin 88 (see Fig. 16). One arm 88 of the bell-crank lever forms the inter-meshing portion of brake 88, while the opposite arm 81 of said bell-crank is associated with a slip-ring clutch element 88 splined to theshaft- 82. A' complementary clutch element 88 is integrally associated with the worm gear 8|, and upon axial movement of the element 88 into clutching engagement with the element 88, rotation of the worm gear 8| is transmitteddirectly to the shaft 82. Movement of the clutch element' 88 into engagement with the clutch eleinent 88 is eii'ected by turning the bell-cranlr-lever "so-that the brake-arm portion 88 thereof is moved to a position releasing the flange Plate 8|, thus permitting its free movementon the hub of flange plate 88.

From the foregoing description of the planetary transmission mechanism it is obvious that rotation of shaft 82 at two different speeds may be effected. With the parts inposition as shown in Fig. 5, flange plate 8| is prevented from rotating by the engagement of the brake-arm 88 with the gear-teeth 86 on the periphery of plate 8|, and the rotation of worm gear 8| is transmittedthrough pinion 88 to gears 88 and 81 which rotate as a unit with the flange plate 88 in a counterclockwise direction viewed from right to left. This motion is transmitted directly to a shaft 82 through the key I08. Upon movement of a crank handle IIII (see Fig. 2) associated with the bell-crank brake-83, simultaneous release of the plate 8| and engagement of the clutch element 88 are effected. In this position, the rotation of worm gear 8| is directly transr ited to the shaft 82 through the clutch elements and the key I02. During clutching en gagement between the elements 88 and 89, ring gear 82, the gears 86 and 81 and the flange plate 80 are all keyed to shaft 82, and consequently, the entire planetary unit rotates as a fly-wheel at the speed imparted to shaft 82 from the worm gear 8|.

vIn order to insure positive tractional engagement at all times between either or both of the oppositely-rotatable traction elements 'I'I, I8 and the sides of the raised templet 'I8, especially when the templet defines a curved path, provision-must be made to compensate-for the rotational variation of the traction elements as they move as a unit about said curved templet. The traction elements l1, 18 must, therefore,-be--capable of bodily rotation as a unit about an axis fmidwar between the same and at a right angle-to the surface supporting the templet. The present invention provides a unit having few rotatable parts, thus minimizing the'inertia forces. incident to its bodily rotation. This unit or differential means is constructed so that positive driving will occur even though one of the traction-propelling elements is disengaged from the templet. The

unit is supported within a housing III rigidly fixed to the transmission casing III. The housing III is counterbored to receive a rotatable steering sleeve or supporting body I" which, in

turn is counterbo'red to receive and support the gle of rotation of sleeve I I1.

The size and length of the eounterbore of steering sleeve II'I provides ample clearance for axial movement of the pinions I28, I2I with respect to. the gear portions I08 and I I8 for a purpose to be described-later.

. r The steering sleeve III'is provided at its lowerextremity with a bearing I22 adapted to support the extended portion of shaft I88 thus main- The variable speed imparted to the shaft 82 may be used to drive the pair of traction-propelling element ll, 18. or the hand-guided pro? taining it as well as the telescoping shaft III in fixed axial position. The ends of the driving shafts I5 and I6, opposite the spur gears I28, I 2| are provided with splined connections I28 and I 24 for transmitting their rotary movement to the traction-propelling elements I1, 18. Thrust collars I28 are pinned to the driving shafts l5 and 18, above the splined connections and in position to abut against the end of the steering sleeve or supporting body I".

An extension I28 of the steering sleeve III is removably secured thereto by a plurality of circumferentially-spaced set screws I21 The extension I26 is bored to receive a traction-propelling unit I28, removably secured thereto by a screw I29. The traction-propelling unit I28 comprises a cylindrical element I36 provided with a pair of spaced bores adapted to receive a pair of shafts I 3 I and I32. The upper extremities of these shafts are provided with fluted socket por-'- tions I33, I34 adapted'to cooperate with the splines I23 and I24, respectively. The lower extremities of these shafts are joumalled for accuracy in antifriction bearings I35 and I36, and support the pair of knurled-headed tractionpropelling elements 11 and 18 which are adapted ciated parts for vertical movement. The recess formed in the counterbored housing II encloses a coiled springI39 in abutting relation with an anti-friction thrust bearing I40 positioned on the upper extremity of the steering sleeve II1. This construction provides means for resiliently urg-- ing the driving means consisting of the shafts 15,16 and pinions I20, I2I towards the lower ends of shafts I03, I04, and also for resiliently urging the traction-propelling elements 11, I8 into driving engagement with the templet 19, while permitting vertical movement of these elements relative to the templet. Since gears I20, I2I reat. all times between the elements 11, 18 and the motor M.

Manually operable means may be provided for moving the traction-propelling elements 11, 18 out of engagement with the templet 19, against the action of spring 39. This has been accomplished by providing a system of levers adapted to be operated from a point near the tracing unit and I Referring .also from a point near the torch T.

to Figs. 2 and '4, a forked lever I4I pivoted to a depending bracket I42 supports rollers I43 in operative engagement with a flange I44 integral with the extension) 26 of the steering sleeve II1. Oscillatable movement of the lever I about its pivot may be effected by the combined'action of a toggle-joint I45 and the spring I39. An arm I46 of the toggle-joint I45 is pivoted to the opposite end of lever I4I from that which supports rollers I43. An arm I41 of a bell-crank lever I48 is pivotally connected to the free end of arm I46 thus completing the toggle-joint construction wmch may be moved to extended or contracted position by a handle I49 associated. with the remaining arm I50 o f the bell-crank lever. I48. An adjustable abutment I55 is located' in position to hold the toggle-joint extended just and attachedto the rod I56, effects the making and breaking of toggle I45. 4

Referring to Fig.7, the interchangeable handguided tracer unit H embodies a rotatable traction disc I59 adapted to be hand-guided along a predetermined pattern within the plane of table T. The oppositely rotatable driving shafts and 16 are adapted to impart rotative moveinent to the disc I 59. These shafts, however, will be bodily rotated about the longitudinal axis of shafts I03 and I04 under the same conditions stated in connection with the bodily rotation of elements 11, 18, and consequently a prov portionate variation in the rotation of these shafts will be effected. Because of this differential action, it is necessary to provide means within the hand-guided traction-propelling unit H which will compensate for or negative the rotational variations of the shafts 15 and 16. In the present instance a differential-compensating mechanism is associated with the unit H and comprises a differential gear train disposed within a cylindrical body portion I60 which is adapted to seat and be secured within the bore of the extension I26. .The body portion I60 is counterboredand bored to receive a pair of sleeve bearings I 6|, I62 for journalling a pair of shafts I63, I64. The upper extremities of these shafts main at all times in mesh with gears I09, IIO,

the arrangement also maintains a positive drive beyond a dead-center position, but permits the;

joint to be broken by movement of the arm I50 in a clockwise direction. In order to facilitate themovement of the traction elements into and out of engagement with the templet from the torch end of the machine, a forwardly extending.

are provided with fluted sockets I65, I66 adapted to cooperate'with the splines I 23, I 24in the same manner that the fluted sockets I33, I34 of shafts I3! and I32 cooperate therewith The lower extremities of shafts I63 and I64'are provided with bevel gears 'I61 and I68, each of which is adapted to engage and drive a compound bevelunit I69 and I10 respectively. Compound bevelunits I69 and I10 are freely mounted at opposite sides of the disc I 59 on a shaft I". The traction-propelling disc I59 is provided with a knurledperiphery circumscribing a spider I12 also mounted to rotate about the shaft "I. A pair pair of removable radial arms of the spider I12,

and mesh with the compound bevel-units I69- and I10. From the foregoing description, it becomes apparent that the opposite rotation of the.

bevel gears I61 and I68 rotate the pair of com pound bevel units I69 and I10 in the same direction about shaft I". The free floating gears I13 and I14 transmit this unidirectional rotation to the disc I59 and they compensate for rotational variations of shafts I63, I 64 incident to bodily rotation of the unit.

The traction-propelling unit just described may be conveniently guided over lines or sketches on thesurface of table T' by means of radially disposed handles I 15 .circumferentially spaced about the flange I44 on the extension I26.

The width of the kerf produced by cutting the I work W is dependent 'upon the bore of the nozzle of torch T, and upon the pressure of the oxygen within the end of .the nozzle at the point wher the jet discharges into the atmosphere. Therefore, when nozzles having different characteristics are used in cutting operations, the

kerf widths produced will be different. The width of the kerf produced under a certain set of operating conditions can easily be-computed from known or determinable data of the particularv nozzle beingused. Ordinarily, it is necessary to form the templet pattern so that its dimensions will compensate or make sufiicient allowance for the width of the kerf produced in the work being shaped. Usually. when it is desired to trace directly from a working drawing or .print or the like, in order to produce a finished shape of the desired dimensions, it becomes necessary to re-draw the working drawing or print to a size, the-dimensions of which are sufficiently changed to make allowance for the kerf which will be produced. Y

The present invention includes a kerf compensation means or means to make allowance, in positioning the torch T, over the work -W,-for kerfs of different widths which may be produced in a cutting operation, said means being associated with the hand-guided tracer unit H, comprising an adjustable pointer I18 located in spaced relation with, and adjacent to the traction disc I58. The pointer I18 extends substantially perpendicularly toward the surface upon which the disk I58 travels,'and is provided with shifting means comprising a counterbored sleeve portion I11 adapted to slidingly engage a hearing block I18 integral with one end of the shaft IN. The internal length of the counterbored sleeve portion is greater than the length of block I18 thus providing a recess for accommodating a coiled spring I18, for a purpose to be described later. A stud I88 is provided with external screw threads at one end adapted to engage corresponding internal threads in the block I18, while the other end of the stud includes an integral flange adapted to engage that portion of the sleeve I11 which forms the outer end of the counterbored recess. An extension of the stud I88 protrudes beyond the sleeve portion I11 and supports an adjusting knob I8l in fixed abutting relation with the outer end surface of the sleeve I11. The coiled spring I18 is adapted to be positioned against the outer end of the bearing block I18 and within the counterboredportion of the bearing sleeve I11 in order to maintain the pointer I18 in adjusted relation by continually urging it and the associated stud. I88 cutwardly, thus increasing thefrictional resistance between the external threads thereof and the corresponding internal threads within the bearing block I18. Rotation of the knob I8I, therefore, causes movement of the pointer I16 to or from the traction disc I58. Thus it will be observed that a pattern may be laid out on the pattern table T to the exact size of the finished piece, or a blue print or sketch of the exact size' of the finished work may be fastened to said table, and by correctly adjusting the position of the pointer I18 and using this pointer as a tracing guide, the traction-propelling means I58 may be located in predetermined positions with respect to the patterns or sketches and may be maintained in the same relative positions throughout the tracing operation. The torch T is thereby propelled over the work W so that sufficient allowance'is made for the width of the kerf produced during the cutting operation, thus permitting a shap of the desired dimensions to be formed. If it is desired to make an over size cut, for instance, to allow for finishing the outer edge of the shape, since the kerf width may be calculated from known data, the tracer-adjustment pointer I18 may be set a distance from the tracer wheel suflicient to allow for the kerf width and oversize, and the pattern traced by the pointer with the tracer wheel outside the pattern or sketch which has been laid out on the table T. Similarly, if it is desiredto make an undersized cut, for instance, to allow for finishing the inside edge of an interior shape, the pointer can be appropriately s t, and the same may then be made to follow the pattern outline with the tracer wheel inside of the" pattern. This arrangement, therefore,

contributes greatly to the precision cutting posit progresses, and to make specific angular cuts,

or to make cuts following a pattern drawn directly on the work to be shaped. This may be accomplished by providing a remote control associated with the steering sleeve II1. Referring to Fig. 4, gear I82 is formed about the periphery of the sleeve 1, and meshes with a spur gear I88 fixed to a vertically disposed shaft I88 joumalled within a lateral extension of the housing, H5. The upper extremity of the shaft I88 is provided with a bevel gear I85 in driving engagement with a similar bevel gear I88 fixed to a. horizontally disposed shaft I81. The rod I81 extends-along and to the front of the carriage I8 (see Fig. 1). Referring to F18. 8, the

, forward end of rod I81 is connected to a tracerdirection actuating device I88 which comprises a housing I88 within which a stub-shaft "I is journalled in alignment with the rod I81. The

, stub-shaft, and rod are joined by a coupling I82.

7 The end of shaft I8I opposite'to. that which supports coupling I82, extendsthrough a side angular cut, and means is provided for locking the same in adjusted position. The a locking means comprises a knob I85 (see Fig. 1) fixed to one end of a shaft, the other end -oi! which .engages the free ends I88 of a friction ring I81. The ring I81 is integral with a plate I88 fixed tothe inside of housing I88, and it is adapted to encircle a brake drum I88 pinned to shaft I 8|. With the above arrangement, it is observed'that when the pointer I88 is set for any given angle. it is possible to out exactly parallel angular cuts by lifting the traction wheel I58from the table T by actuating the hancfle I88 or I58, and moving the carriages over any desired distance without altering the previous For the purpose of making bevel cuts in accordance with a. curvilinear templet pattern, an interchangeable attachment B is adaptedto be employed, which operates to turn the torch T about its longitudinal axis in accordance with,

and proportional to the turning of the templetsleeve 20] is in vertical position.

When the tracer mechanism P travels along a curved templet, its rotational movement is transmitted to the steering rod I81, and this motion must be further transmitted to the sprocket 204 so; that the torch T and its bevelcutting nozzle will be rotated in accordance with V the rotation" of the mechanism P. This has been accomplished by providing an opening in the top portion of housing I90 within which a vertically disposed bearing sleeve 205 is positioned. -A stub shaft 206 is Journalled in the sleeve 205, extending to a point within housing I90 adjacent to shaft I9I, and to a point outside of said housing, and upon which a sprocket 201 is fixed in alignment with the sprocket 204. The lower end of shaft 206 is provided with a bevel gear 208 which meshes with a similar bevel gear 209 pinned to shaft I 9|. A driving connection between sprockets 204 and 201 is established by a sprocket chain 2I0 enclosed by a chain guard 2| I.

A dual control feature which facilitates the operation of the apparatus comprises an electrical control box 2I2 mounted on, and near the rear of the upper carriage I 9, as shown in Fig. 1. This box is provided, as at S, with three switches, namely, a forward, a reverse, and a stop switch, all of which are appropriately connected in an electrical circuit receiving current from the power supply connection 2 I3. Branches of the above-mentioned circuit extend within the upper carriage I9 to a duplicate control box 2 located at the forward end thereof. The.

control box 2 It is provided with a set of switches S similar to those in box 2I2, and connected in parallel therewith.

It is often desirable to observe the speed of cutting, or movement of the carriage mechanism at the forward end of the machine as well as at the tracing portion thereof. Accordingly, a suitably calibrated speed indicator ZIE ismounted in operative relation with the motor M. A drive shaft 2I6 universally connected to the indicator 215 extends through the upper carriage I8 to a similar speed indicator 2I'l mounted on a panel of the control box 2M. Thus, it is observed that the operator may conveniently control the operation of the machine from either the tracing, or the cutting-torch portion thereof.

Referring to Fig. 1 of the drawings, the pattern table T is shown disposed between the pair of rails I2 and It. The apparatus supporting table II is adapted to accommodate a pair of supports 2I8 adjacent each edge thereof, only one of which is shown. The supports 2I8 are made up of two identical rods in closely spaced relation for receiving T-headed bolts 2I0 which in turn are arranged to lock in place, respective plate-sections 220 of polished aluminum alloy vide a level surface at the joints. The plates 220 are further provided at each end with apertures adapted to receive the shanks of T-headed bolts 2I9. By simply loosening these T-headed bolts, without removing them, the aluminum tracing-table plates 220 may be separated and moved along the table frame as desired, thus facilitating the mounting of templet supports 22I in any position along the table length. This latter function maybe accomplished by providing hold-down means in the form of. clamps 222 adapted to be positioned between adjacent plates 220 when the same are separated.

It will be understood that the arrangement above described makes it possible for the templet supports 22I to be firmly secured to the table top with no possibility of accidental shifting during operation of themachine. For hand tracing, designs may also be clamped to the table whether they be drawn on paper orother material. The construction of the surface of table T provides excellent traction for the wheel I59 of the handguided tracing unit H, sothat if desired, a pattern may be drawn directly onthe aluminum surface, the cut made, and the pattern easily erased. I i

The present invention is not limited to the exact structure and arrangement shown, but is intended to embrace similar and equivalent ele-v ments, and features having an equivalent relative arrangement. The particular structure shown as an example of a preferred embodiment of the invention may be of different form and relative arrangement without departing from the spirit of the invention or the scope of the claims.

What is claimed is:

1. A metal-working machine comprising in combination a pair of carriages adapted to move along mutually perpendicular paths for conveying a thermal implement universally in a plane over a workpiece; a motor rigidly mounted on one 1 driven traction elements severally operatively connected with said drive elements, whereby rotational movement of said support incrementally sincreases and decreases the rotation of said respective traction elements positively inaccordance with the direction ofrotation of said support to an extent proportional to the angle of said rotational movement.

2. A metal-working machine comprising in combination a pair of carriages adapted to move along mutually perpendicular paths for conveying a thermal implement universally in a plane over a workpiece; a motor rigidly mounted on one of said carriages; a pair of axially aligned oppositely rotatable driving means connected to said motor; va support rotatablymounted relative to said motor; a pair of spaced drive elements car-' ried by said support and in driving engagement with said respective driving means, whereby rotational movement of said support incrementally increases and decreases the rotation of said drive elements in accordance with the direction of rotation of said support to an extent proportional to the angle of said rotational movement;

and a traction-propelling device comprising a traction disc driven by said elements and adapted to tractionally engage a plane surface, and means associated with said disc for negativing the effect of the incremental increases and decreases -in rotation of the respective drive elements when said support is rotated.

3. A metal-working machine comprising in combination a pair of carriages adapted to move along mutually perpendicular paths for conveying a thermal implement universally in 'a plane over a workpiece; a motor rigidly mounted on one of said carriages; a pair of axially aligned oppositely rotatable driving means connected to said' motor; a support rotatably mounted relative to.

said motor; a pair of spaced drive elements carried by said support and in driving engagement with said respective driving means, whereby rotational movement of said support incrementally increases and decreases the'rotation of said drive elements in accordance with the direction of rotation of said support to an extent proportional to rigidly mounted on one of said carriages; a propelling unit adapted to tractionally engage 9.

' power shaftpa pair of spaced traction elements adapted to engage and travel along a templet; and driving means associated with said elements and engaging said drive shafts and being so posipositive driveconnections therebetween.

'7. A combined transmission and differential means for a propelling unit comprising means for driving a power shaft at a-piurality of speeds; a

pattern for guiding said implement along a predetermined path; transmission mechanism in driven engagement with said motor; and diflerential means operatively connecting said trans mission and, said propelling unit, said differential means comprising a pair of mutually telescoped shafts'both positively driven by said motor at uniform speed in opposite directions, and spaced driving elements each in driving engagement with one of said shafts, said elements being' revolvable about the periphery of said respective positively driven shafts as said unit turns in following said path, thereby to increase and decrease the speed of rotation of said respective n elements. a

5. A machine comprising in combination a pair of carriages adapted to be moved along D mon dicular paths for conveying an implement universally in a plane over a workpiece; a motor rigidly mounted on one of said carriages; a'pro- .pelling unit adapted to tractionally engage a pattern; a variable speed transmission in driven engagement with saidmotor; and differential means operatively connecting said transmission and said propelling unit, said differential meanscomprising a pair of oppositely rotatable mutual.- ly telescoped shafts, and spaced drivingelements each in driving engagement with one of said shafts, said propelling unit comprising'a disc. adapted to tractionally engage a plane surface,

pair of mutually telescoping drive shafts adapted to be oppositely rotated simultaneously bysaid 1 power shaft; a pair of spaced traction elements adapted to positively engage and travel along a templet; driving means associated with said elements and so positioned with respect to said drive shafts that relative axial movement between the elements and the shafts may be effected while.

interchangeably support an automatic templetfollowing device and a hand-guided tracing device in positive driving relation with said shafts.

9..A shape-cutting machine comprising a pair of carriages adapted to be moved along mutually perpendicular paths for transporting a shape cutting implement over work to be shaped; a motor rigidly mounted on one of said carriages against relative movement with respect thereto; variable speed transmission means connected to said motor for rotating a .pair of telescoping driven members in opposite directions; a rotatable support and a pair of spaced shafts carried by said support in position to be rotated in opposite directlons by said driven members, said support being arranged to interchangeably support an automatic templet-following unit and a handguided tracing device.

10. A shape-cutting machine comprising a pair of carriages adapted to be moved along perpendicular paths for transporting a shape-cutting implement over work to be shaped; a motor rigidly mounted on one of said carriage's'against relative movement with respect thereto; variable speed transmission means connected to said motor for rotating a pair of telescoping driven members in opposite directions; a support, adapted to be turned about the axis of said driven members for supporting a pair of spaced shafts in position to be rotated in opposite directions by said driven members; a unit engageable with said support and having a pair of traction-propelling elements in position to bedriven by said shafts; and -an interchangeable unit engageable with said support and having a single tractionpropelling element in position-to be driven by said shafts and'incorporating means adapted to compensate for rotational variationsof said shafts when said support is turned about the aids of said driven members. 7 I

11. A shape-cutting machine comprising in combination, a pair of carriages for moving a shaped; a motor mounted against relative movement with respect to one oi. said carriages; a combined variable speed transmission and differential unit; apair of oppositely rotatable shafts connected by said unit inpositive driving engagement with said motor; a single tractionpropelling element driven by said shafts; and

means for bodily turning said traction-propelling element independently of ,both such motormounting, and said transmission and 'difi'eren-' tial unit.

12. A shape-cutting machine comprising a pair of carriages provided with rollers and arranged for movement along perpendicular sets of tracks,

a cutting implement mounted on one of said carriages; traction-propelling means for universally moving said cutting implement in a plane over work to be shaped; and spring-activated means on each carriage adapted to frictionally a cutting implement mounted 'on said secondcarriage; traction-propelling means adapted to move said cutting implement universally in a plane over work to be shaped; brake shoes; resilient means adapted to urge said shoes into frictional engagement with the rolling surface v of at least one roller of each of said carriages to v inhibit the motion of said carriages along their respective rails, thereby to restrict the movement of said cutting implement over said work to straight lines; and manually operable lever means adapted to release said brake shoes from engagement with such rollers, whereby said cutting implement may then be moved universally over said work. I

14. A shape-cutting machine comprising a cutting torch adapted to be universallymoved in a plane; a hand-guided traction-propelling unit adapted to move said torch in accordance with a predetermined pattern; and pointer means attached to said unitin spaced adjustable relation with respect thereto, said pointer means being adapted to follow the outline of said pattern for locating said unit in predetermined positions laterally with respect to the outline of said pattern to thereby compensate for kerfs of difierent widths which may be produced in cutting with said torch. 15. A shape-cutting machine comprising a carriage and a cutting torch adapted to be moved universally in a plane over work to be shaped; traction means associated with said carriage including a propelling disc adapted to engage tractionallya plane surface for propelling said carriage and for moving said torch in accordance with a predetermined pattern; kerf-compensation means comprising a pointer secured to said traction means adjacent to said disc and extending substantially perpendicularly toward said surface for location directly above the outline of said pattern, and shifting means for moving said pointer laterally toward and away from said disc to locate said disc in laterallyspaced relation to said outline, said ken-compensation means thereby being adapted to compensate in the size of the finished work for kerfs of different widths which may be. produced in cutting with said torch. V f

v 16. A shape-cutting machine comprising a pair of carriages adapted tobe moved along mutually perpendicular paths, one of said carriages being adapted to support a cutting torch for movement over work to be shaped; a motorrigidly mounted on. one of said carriages; oppositely rotatable axially aligned driving means in driving engagement with said motor; rotatable means for supporting hand-guided traction-propelling means,

said rotatable means comprising a pair of spaced shafts in driving engagement with said propelling means and said driving means; and means associated with said rotatable means for rotating said torch about its longitudinal axis in accordance with the rotation of said rotatable means and independently of said motor.

17. A shapeecutting machine comprising a pair of carriages adapted to be moved along mutually perpendicular paths, one of said carriages being adapted to support a cutting torch for movement over work to be shaped; a motor rigidly mounted on one of said carriages: oppositely rotatable axially aligned driving means in positive driving engagement with said motor; rotatable means for supporting traction-propelling means, said rotatable means including a pair of laterally spaced shaftsconnecting said propelling means with 7 said driving means; remote-control means associated with said rotatable means and adapted to control the movement of said traction-propelling means; and. means associated with saidremotecontrol means for rotating said torch about its longitudinal axis in accordance with the rotation of said rotatable means and independently of said motor.

18. A shape-cutting machine comprising a pair of carriages adapted to be moved along mutually perpendicular paths; a cutting torch associated with one of said carriages; a motor rigidly mounted on one of said carriages; oppositely rotatable axially aligned driving means in driv ing engagement with said motor; a rotatable control the movement of said hand-guided-tracing means; and a torch support including means for rotating said torch about its longitudinal axis when said traction-propelling device is rotated about its longitudinal axis, andin accordance with the degree of rotation of said device, as either of said templet-following or hand-guidedtracing means follows a curved templet or a curved path.

19. A shape-cutting machine comprising .a

lower carriage adapted to be moved along a pair of rails; an upper carriage adapted to be moved along a pair of rails mounted on said lower carriage at right angles to the lower-carriage rails; a plurality of pairs of upper and lower rollers mounted on said upper carriage at points spaced longitudinally thereof and adapted to engage the upper and lower surfaces respectively, of the rails of said upper carriage; and connecting means mounting one pair of said lower rollers to said'upper carriage for self-adjusting movement of said connecting means relative to said carriage.

upper carriage and independently of the remaining pairs of said rollers for insuring constant engagement of such mounted pair of lower rollers with the under surface of the rails of said upper 20. a shape-cutting machine as claimed in claim 19 in'which said connecting means comprises a self-adjustable, pivoted mounting for said pair 'of lower. rollers.

21. A shape-cutting machine comprising an upper and lower carriage adapted to be moved along mutually perpendicular paths; a cutting means as when following a curved complete operation of said machine may be traction end of said machine, said dual control means including'means at-spased points alon said upper carriage for starting, stopping, or

reversing the operation of a motor connected to said traction-propelling device; and means at spaced points along said upper carriage for concutting torch.

22, A shape-cutting machine comprising a pair of carriages adapted to be moved along mutually perpendicular paths; a traction-propelling device associated with said carriages and comprising a pair of oppositely rotatable shafts; a variable speed transmission including a planetary geartrain; a simultaneously operable brake and clutch means cooperable with said train for c a the speed of said transmission; and.diiferentlal eifected from the torch end aswell as from the trolling the flow of oxygen and acetylene to said age-(aces means connecting said traction-propelling device and said variable speed transmission, so constructed and arranged that bodily turning of said device eifectsdifferential rotation of said pair of oppositely rotatable shafts.

23. A traction-propelling unitfor use with a machine adapted to be moved universally over work, comprising in combination, a pair of laterally spaced parallel shafts having means adapted to frictionally engage a raised templet; a motor; oppositely rotatable means positively driven by said motor for driving both of said shafts posi-' tively in opposite directions; and means for supporting said shafts relative to said driving means sothatduringbodilyturningoisaidshaftswith said supporting means as a unit relatively to said templet, said shafts cooperate with said oppositely rotatable means to positively decrease and positively increase the rates of rotation of the respective'shaits depending upon the direction and speed at whichsaid shafts are turned as a unit.

24. A traction-propelling unit as claimed in claim 23, in which said driving means comprises axially aligned oppositely rotatable means positioned at the axis of said supporting means at equal distances from and in driving engagement with said laterally spaced shafts.

25. A traction-propelling unit as claimed in claim 23 in which said oppositely rotatable driving means includes a pair of pinions located axially with respect to said supporting means and in driving engagement with pinions on the respective laterally spaced shafts.

SAMUEL n. OLDHAM. 

